Rat hepatoma cells in tissue culture have been shown to possess the conjugating enzyme system for glucuronylation. Cultured cells grown shell side in hollow-fiber devices have been shown to exchange nutrients and metabolites through the walls of semi-permeable hollow fiber membranes with tube side fluids. It is proposed to 1) develop a device within which cultured cells will proliferate to form a coherent cell lining; 2) establish the cell lining using rat hepatoma cells; 3) evaluate the ability of hemoperfused cells in an extracorporeal circuit with the rat to perform detoxification and other liver-related functions.